Transplantation in Special Populations — MCQs
HLA typing is useful in:
Which of the following is true regarding extended criteria donors for liver transplantation?
Which of the following is not true about lupus nephritis in pregnancy?
What is the most common viral illness transmitted via homologous blood transfusion?
Most common infection post solid organ transplantation
What is the most common type of graft rejection?
After the first postoperative year of cardiac transplantation, what is the most common cause of death?
Infection in a renal transplant patient is usually caused by which pathogen?
Which of the following should be avoided in the long-term follow-up of a renal transplant recipient on ciclosporin?
What type of graft is a graft from a sister to a brother?
Transplantation in Special Populations Indian Medical PG Practice Questions and MCQs
Question 1: HLA typing is useful in:
- A. Disputed paternity
- B. Dactylography
- C. Organ transplant (Correct Answer)
- D. Thanatology
Explanation: ***Organ transplant*** - **HLA typing** is crucial for **matching donors and recipients** in organ transplantation to minimize the risk of transplant rejection [1]. - A better **HLA match** between donor and recipient reduces the likelihood of the recipient's immune system attacking the transplanted organ [1]. *Disputed paternity* - While **HLA typing** was historically used, **DNA fingerprinting** (using STR markers) is now the primary and more accurate method for determining paternity [2]. - **DNA analysis** provides a higher probability of inclusion or exclusion and is less complex to interpret than HLA typing for paternity [2]. *Dactylography* - **Dactylography** refers to the study of fingerprints for **identification purposes**, a field entirely unrelated to genetic markers. - It involves analyzing the unique patterns of **ridges and valleys** on fingertips, not genetic typing. *Thanatology* - **Thanatology** is the scientific study of **death and dying**, including the psychological, social, and cultural aspects. - It does not involve genetic testing like **HLA typing** but rather focuses on end-of-life care, grief, and the processes surrounding death.
Question 2: Which of the following is true regarding extended criteria donors for liver transplantation?
- A. Donors with well-controlled diabetes mellitus
- B. Hepatitis C antibody positive donors
- C. Donors with significant uncontrolled comorbidities
- D. Donors aged >60 years with no significant comorbidities (Correct Answer)
Explanation: ***Donors aged >60 years with no significant comorbidities*** - **Advanced donor age** is a key characteristic of an extended criteria donor (ECD), especially when coupled with other factors like **ischemic time** or comorbidities. - While age alone might not prohibit donation, it puts the donor liver into the ECD category, requiring careful recipient selection and possibly increasing the risk of **post-transplant complications**. *Donors with well-controlled diabetes mellitus* - **Well-controlled diabetes mellitus** in a donor does not automatically classify them as an extended criteria donor, if there are no other significant associated comorbidities or organ damage. - The focus is generally on signs of significant end-organ damage or poorly controlled disease that could impact graft function. *Hepatitis C antibody positive donors* - **Hepatitis C antibody positive donors** are traditionally considered extended criteria donors and remain classified as such. - However, with the advent of highly effective **direct-acting antiviral (DAA) therapies**, HCV-positive organs can now be safely transplanted into both HCV-positive and HCV-negative recipients with excellent outcomes. - While still technically ECD, the clinical significance has diminished significantly with modern treatment availability, making **donor age >60 years** the more universally recognized ECD criterion in current practice. *Donors with significant uncontrolled comorbidities* - **Significant uncontrolled comorbidities** would generally render a donor **unsuitable for donation**, rather than classify them as an extended criteria donor. - Extended criteria typically refer to factors that increase risk but are still acceptable under specific circumstances, whereas uncontrolled comorbidities often pose too high a risk for successful transplantation.
Question 3: Which of the following is not true about lupus nephritis in pregnancy?
- A. Ecosprin, methotrexate, cyclophosphamide, corticosteroids, azathioprine are safe in pregnancy (Correct Answer)
- B. Pregnancy to be planned once the disease has been quiescent for at least 6 months and there is no evidence of renal dysfunction
- C. High dose corticosteroids for lupus flare in pregnancy is safe
- D. Immunosuppression can be continued during pregnancy
Explanation: ***Ecosprin, methotrexate, cyclophosphamide, corticosteroids, azathioprine are safe in pregnancy*** - This statement is **incorrect** because **methotrexate** and **cyclophosphamide** are **contraindicated** in pregnancy due to their teratogenic effects, while **ecosprin (aspirin)** and some **corticosteroids** and **azathioprine** are generally considered relatively safe at appropriate doses. - The combination of **safe and unsafe drugs** within the same statement makes the entire statement untrue; a pregnant patient with lupus nephritis cannot safely take all listed medications. *Pregnancy to be planned once the disease has been quiescent for at least 6 months and there is no evidence of renal dysfunction* - This statement is **true** and represents a **standard recommendation** for managing lupus nephritis in pregnancy. Achieving disease quiescence for at least 6 months significantly reduces the risk of flares and adverse pregnancy outcomes. - Ensuring **absence of renal dysfunction** before conception is crucial to prevent complications like pre-eclampsia, worsening renal function, and prematurity. *High dose corticosteroids for lupus flare in pregnancy is safe* - This statement is **true**. High-dose corticosteroids, such as **prednisone** or **prednisolone**, are often used to manage lupus flares during pregnancy. - These corticosteroids are largely **inactivated by placental enzymes**, minimizing fetal exposure and making them relatively safe for the fetus, while effectively treating maternal disease. *Immunosuppression can be continued during pregnancy* - This statement is **true**. Certain immunosuppressants, like **azathioprine** and **calcineurin inhibitors**, are considered relatively safe and are often continued during pregnancy to prevent disease flares. - **Continuing safe immunosuppression** helps maintain disease control, which is essential for a successful pregnancy outcome in patients with lupus nephritis.
Question 4: What is the most common viral illness transmitted via homologous blood transfusion?
- A. Hepatitis C (HCV)
- B. HIV
- C. Hepatitis B (HBV) (Correct Answer)
- D. Cytomegalovirus (CMV)
Explanation: **Hepatitis B (HBV)** - Although screening has significantly reduced the risk, **Hepatitis B (HBV)** remains a frequently transmitted viral infection through homologous blood transfusion due to its relatively **high viremia** and occassional **'window period'** infections that can evade detection [1]. - HBV also has a significant global prevalence, contributing to its ongoing presence as a risk despite rigorous testing protocols [1]. *Hepatitis C (HCV)* - While historically a leading cause of post-transfusion hepatitis, advanced **nucleic acid amplification testing (NAAT)** has dramatically reduced the risk of HCV transmission via blood products [1]. - The **prevalence of HCV** in the general population coupled with sensitive screening tests means it is now less commonly transmitted than HBV through transfusion [1]. *HIV* - The risk of **HIV transmission** through blood transfusion is exceedingly low in developed countries due to highly effective and sensitive screening methods, including **NAAT** and antibody tests [1]. - While devastating, the **incidence of transfusion-related HIV** is rare due to stringent donor selection and testing [1]. *Cytomegalovirus (CMV)* - **CMV** transmission through blood transfusion is a concern primarily in **immunocompromised recipients** (e.g., neonates, transplant patients) where it can cause significant morbidity. - For the general population, CMV infection from transfusion is often subclinical or mild, and leukoreduction of blood products has further reduced its transmission risk [1].
Question 5: Most common infection post solid organ transplantation
- A. EBV
- B. CMV (Correct Answer)
- C. HSV
- D. HPV
Explanation: ***CMV*** - **Cytomegalovirus (CMV)** is the most common viral infection in solid organ transplant recipients, often reactivating in immunosuppressed patients [1]. - It can cause a wide range of clinical syndromes including **fever**, **leukopenia**, **hepatitis**, **pneumonitis**, and **gastroenteritis**, and is a significant cause of morbidity and mortality [1]. *EBV* - **Epstein-Barr virus (EBV)** is also common in transplant recipients but is most notably associated with **post-transplant lymphoproliferative disorder (PTLD)**, a serious complication [1]. - While present, it is not as frequently the cause of symptomatic infection as CMV in the immediate post-transplant period. *HSV* - **Herpes simplex virus (HSV)** infections can occur, manifesting as mucocutaneous lesions or, less commonly, severe systemic disease in transplant patients. - However, its incidence and severity are generally lower compared to CMV in the overall transplant population. *HPV* - **Human papillomavirus (HPV)** infections are typically associated with **warts** and increased risk of **malignancies** (e.g., anogenital cancers) in immunosuppressed individuals, including transplant recipients. - While important for long-term surveillance, HPV does not represent the most common acute infection post-transplant.
Question 6: What is the most common type of graft rejection?
- A. Hyperacute
- B. Acute (Correct Answer)
- C. Chronic
- D. Acute on chronic
Explanation: ***Acute*** - **Acute rejection** is the most common type of graft rejection, occurring in **10-40% of transplant recipients**. [1] - It typically occurs **days to weeks to months** after transplantation (most commonly within the first 6 months). [1] - Mediated primarily by **T-lymphocytes** (cellular rejection) or **antibodies** (antibody-mediated rejection) reacting against donor antigens. [1] - Usually **responsive to immunosuppressive therapy** when detected early. *Hyperacute* - **Hyperacute rejection** is rare (occurs in <1% of cases) due to routine **pre-transplant cross-matching**. - Occurs within **minutes to hours** after transplantation due to **pre-existing circulating antibodies** against donor antigens. [1] - Results in immediate thrombosis and graft necrosis, requiring **immediate graft removal**. [1] *Chronic* - **Chronic rejection** (chronic allograft dysfunction) develops **months to years** after transplantation. - It is the **most common cause of late graft failure**, but not the most common type of rejection episode. - Characterized by **gradual, progressive loss of graft function** with vascular and fibrotic changes. - **Largely irreversible** and poorly responsive to treatment. *Acute on chronic* - This is **not a primary category** of graft rejection but represents an **acute rejection episode superimposed** on a graft already undergoing chronic changes. - Reflects exacerbation in a chronically rejecting graft. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of the Immune System, pp. 239-242.
Question 7: After the first postoperative year of cardiac transplantation, what is the most common cause of death?
- A. Infection
- B. Arrhythmia
- C. Accelerated graft arteriosclerosis (Correct Answer)
- D. Acute rejection episode
Explanation: **Explanation:** The survival of cardiac transplant recipients is divided into two distinct phases: the early postoperative period (within the first year) and the late postoperative period (after one year). **Why 'Accelerated Graft Arteriosclerosis' is correct:** Also known as **Cardiac Allograft Vasculopathy (CAV)**, this is a unique, progressive form of chronic rejection. Unlike typical atherosclerosis, CAV is characterized by diffuse, concentric intimal proliferation affecting the entire length of the coronary arteries. It remains the leading cause of late mortality (after 1 year) because the denervated heart does not experience typical angina, often leading to silent myocardial infarction, heart failure, or sudden death. **Why the other options are incorrect:** * **Infection:** This is the **most common cause of death within the first year** (specifically the first 30 days to 6 months) due to intense induction immunosuppression. * **Acute Rejection:** This typically occurs within the first 3–6 months. While it remains a risk, its incidence decreases significantly after the first year due to maintenance therapy. * **Arrhythmia:** While arrhythmias can occur due to surgical trauma or acute rejection in the early phase, they are rarely the primary cause of late-term mortality unless secondary to CAV. **High-Yield Clinical Pearls for NEET-PG:** 1. **Most common cause of death (<1 year):** Infection. 2. **Most common cause of death (>1 year):** Cardiac Allograft Vasculopathy (CAV) / Graft Arteriosclerosis. 3. **Gold Standard for CAV diagnosis:** Annual coronary angiography with **Intravascular Ultrasound (IVUS)**, as angiography alone may underestimate the diffuse narrowing. 4. **Malignancy:** The risk of lymphomas (PTLD) and skin cancers increases significantly in the late phase due to long-term immunosuppression.
Question 8: Infection in a renal transplant patient is usually caused by which pathogen?
- A. Cytomegalovirus (CMV) (Correct Answer)
- B. Human Immunodeficiency Virus (HIV)
- C. Herpes Simplex Virus (HSV)
- D. Salmonella
Explanation: **Explanation:** **Cytomegalovirus (CMV)** is the most common clinically significant opportunistic viral pathogen in renal transplant recipients. It typically manifests between **1 to 6 months post-transplant**, coinciding with the period of maximal immunosuppression. The infection occurs due to primary infection (seronegative recipient receiving a seropositive organ), reactivation of latent virus, or superinfection. CMV is high-yield because it not only causes systemic symptoms (fever, leukopenia) and organ-specific disease (pneumonitis, hepatitis, colitis) but also acts as an immunomodulator, increasing the risk of graft rejection and other opportunistic infections. **Analysis of Incorrect Options:** * **HIV (Option B):** While HIV is a significant viral pathogen, it is not a common "post-transplant infection." In fact, HIV-positive status was previously a contraindication to transplant, though "HIV-to-HIV" transplants are now performed in specific protocols. * **HSV (Option C):** Herpes Simplex Virus can cause mucocutaneous lesions in the early post-operative period, but its incidence has significantly decreased due to routine prophylactic use of Acyclovir/Valacyclovir. It is less common and less severe than CMV. * **Salmonella (Option D):** While transplant patients are at higher risk for intracellular bacterial infections like Salmonella, it is far less frequent than viral pathogens like CMV. **High-Yield Clinical Pearls for NEET-PG:** * **Timeline of Infection:** * *<1 month:* Bacterial infections (UTI, wound infection) and donor-derived infections. * *1–6 months:* **CMV (Peak incidence)**, BK virus, and opportunistic infections (PJP). * *6+ months:* Community-acquired pneumonia or chronic viral infections (HCV, HBV). * **Diagnosis:** Quantitative PCR for CMV DNA is the gold standard. * **Treatment:** Intravenous **Ganciclovir** or oral Valganciclovir. * **Prophylaxis:** Most centers use Valganciclovir for 3–6 months post-transplant to prevent CMV.
Question 9: Which of the following should be avoided in the long-term follow-up of a renal transplant recipient on ciclosporin?
- A. Administer live vaccines
- B. Prescribe drugs that inhibit cytochrome P450 activity
- C. Prescribe NSAIDs
- D. All of the above (Correct Answer)
Explanation: In renal transplant recipients on long-term immunosuppression with Ciclosporin, management focuses on preventing graft rejection, avoiding nephrotoxicity, and managing drug-drug interactions. **Explanation of Options:** * **A. Live Vaccines:** Immunosuppressed patients (on Ciclosporin, Tacrolimus, or Mycophenolate) have a diminished immune response. Administering live-attenuated vaccines (e.g., BCG, MMR, Yellow Fever) carries a significant risk of causing disseminated infection from the vaccine strain itself. * **B. Cytochrome P450 (CYP3A4) Inhibitors:** Ciclosporin is extensively metabolized by the hepatic CYP3A4 enzyme system. Drugs that inhibit this system (e.g., Erythromycin, Ketoconazole, Diltiazem) decrease Ciclosporin metabolism, leading to toxic blood levels. Conversely, CYP inducers (e.g., Rifampicin, Phenytoin) lower levels, risking graft rejection. * **C. NSAIDs:** Ciclosporin causes vasoconstriction of the afferent arterioles, reducing renal blood flow. NSAIDs inhibit prostaglandins, which are necessary to maintain afferent arteriolar vasodilation. Combining the two leads to synergistic pre-renal vasoconstriction and acute-on-chronic nephrotoxicity. **Clinical Pearls for NEET-PG:** * **Gingival Hyperplasia:** A classic side effect of Ciclosporin (also seen with Phenytoin and Nifedipine). * **Monitoring:** Therapeutic Drug Monitoring (TDM) is essential for Ciclosporin due to its narrow therapeutic index. * **Metabolic Profile:** Ciclosporin is associated with "H" side effects: **H**ypertension, **H**yperlipidemia, **H**yperglycemia, **H**irsutism, and **H**yperkalemia. * **Tacrolimus vs. Ciclosporin:** Tacrolimus is more potent and lacks hirsutism/gingival hyperplasia but has a higher incidence of New-Onset Diabetes After Transplantation (NODAT).
Question 10: What type of graft is a graft from a sister to a brother?
- A. Isograft
- B. Allograft (Correct Answer)
- C. Autograft
- D. Heterograft
Explanation: ### Explanation The correct answer is **Allograft (Option B)**. **1. Why Allograft is correct:** An **allograft** (or homograft) is a transplant between two genetically non-identical members of the same species. Since a brother and sister share approximately 50% of their genetic material (unless they are monozygotic twins), they are genetically distinct individuals. Therefore, any organ or tissue transfer between them is classified as an allograft. This requires immunosuppression to prevent T-cell mediated rejection. **2. Why other options are incorrect:** * **Isograft (Option A):** This is a graft between genetically identical individuals. In humans, this only occurs between **monozygotic (identical) twins**. Since the question specifies a brother and sister (who are dizygotic/siblings), they cannot be genetically identical. * **Autograft (Option C):** This involves a graft taken from one part of a patient's body and transferred to another part of the **same individual** (e.g., a skin graft from the thigh to the arm or a CABG using the radial artery). There is no risk of rejection. * **Heterograft (Option D):** Also known as a **Xenograft**, this is a transplant between members of **different species** (e.g., a porcine/pig heart valve transplanted into a human). **3. Clinical Pearls for NEET-PG:** * **Hyperacute Rejection:** Occurs within minutes to hours due to pre-formed antibodies (Type II Hypersensitivity). * **Acute Rejection:** Occurs within days to weeks; primarily T-cell mediated (Type IV Hypersensitivity). * **Chronic Rejection:** Occurs months to years later; characterized by fibrosis and vascular occlusion. * **Order of Immunogenicity:** Xenograft > Allograft > Isograft = Autograft. * **Graft-versus-Host Disease (GVHD):** Most common in bone marrow transplants where donor T-cells attack the recipient's tissues.
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